To evaluate the factors affecting successful occlusion treatment and visual recovery time in patients with amblyopia when best corrected visual acuity (BCVA) improved up to 1.0 after occlusion.

Forty-eight patients aged 2 to 13 years old with amblyopia due to refractive errors or strabismus were selected. The duration of treatment needed to achieve a BCVA of 1.0 was compared according to the cause of amblyopia (anisometropia, strabismus, combined), initial BCVA of the amblyopic eye, and the age at treatment, as well as other factors.

The mean age of amblyopic treatment was 5.4 years old and the mean duration of treatment was 22.9 months. The duration of treatment was longer in children whose initial BCVA was lower than 0.2, those with spherical equivalent of the amblyopic eye higher than +3.0D and those older than 6 years old. However, there were no significant differences according to the cause of amblyopia.

The duration of treatment needed to achieve a BCVA of 1.0 was prolonged when the initial BCVA in the amblyopic eye was lower than 0.2, the age at treatment was more than 6 years old, or the spherical equivalent of the amblyopic eye was higher than +3.0D at treatment. These factors can be used to predict the duration of occlusion treatment.